A flail chest is a condition that occurs when multiple adjacent ribs are broken, separating a segment of the chest wall so that it becomes detached from the rest of the chest wall and moves independently therefrom. This detached segment moves in the opposite direction as the rest of the chest wall, moving inward while the rest of the chest is moving outward and vice versa, creating “paradoxical motion” that increases the effort and pain involved in breathing.
Most rib fractures are treated conservatively using pain management and/or bracing techniques. Fractured ribs in a flail chest treated in such a manner may undergo progressive displacement during the healing phase, resulting in considerable deformity, volume loss, atelectasis, and chronic pain. Long-term problems of patients with flail chest injuries treated nonoperatively include subjective chest tightness, thoracic cage pain, and dyspnea.
Four categories of fixation devices for operative chest wall fixation have been utilized, namely plates, intramedullary devices, vertical bridging, and wiring. The results of these repair techniques are often less than desirable because of the difficulty in correctly locating the broken rib ends with one another. Stabilizing rib fractures is challenging because large incisions are typically needed to accommodate fixation, which leads to a more morbid procedure. In addition, ribs are narrow with a thin cortex that surrounds soft marrow, making reliable fixation problematic under conditions that include upwards of 25,000 breathing cycles per day, as well as coughing. Still further, there is risk of damage to the neurovascular bundle.
Currently, the surgery involves a significant operative procedure with mobilization of large chest wall flaps or open thoracotomy. The problems and risks of an operative approach include the surgical trauma itself and the loosening and migration of implants. The surgery involves a major incision through the muscle directly down to the ribs, which can have complications such as loss of muscle function, blood loss, and damage to surrounding vascular and neural tissue. The ribs that are to be fixed need to be adequately exposed in order to obtain a good placement of metal fixation plates. A wide incision is performed, and myocutaneous flaps may need to be raised to allow visualization of all segments. Posterior injuries are usually challenging due to the presence and required exposure of large muscle fibers (e.g., latissimus dorsi, trapezius, rhomboids, paraspinous muscles). The procedure utilized in current practice is typically at least three hours in length with an additional hour required for the closing of the surgical exposure.